1. Field of Industrial Application
This invention relates to solid form electrolyte composites employed to fabricate various solid electrochemical products such as batteries, capacitors, sensors, display devices, recording devices, etc.
2. Prior Art
It had been known that various electrochemical devices such as compact and thin batteries, double layered electrical capacitors, etc., can be constructed without leakage of liquid electrolyte by employing a solid electrolyte. However, since such solid electrolytes lack mechanical elasticity, they are brittle or highly vulnerable against even a slight mechanical shock.
In order to solve such problem, various methods had been proposed. Among these, Japanese Laid-Open Patent 5h0 63-245871 discloses a method to produce electrochemical devices of high mechanical strength against shock by preparing a composite of ionic inorganic compound and elastomer, and a report "Fast Ion Transport in Solid" (by P. Vanishsta et al., Eds. P. 131 (1979) North Holand Publishing Co.) discloses a solid polymer electrolyte comprised of polyethylene-oxide (PEO) and alkaline metallic salt.
However, because of the poor chemical stability of such ion-conductive inorganic compounds, handling those compounds is a highly difficult matter in general. Among these, alkal metal ion conductors are particularly difficult to handle because of their chemical instability and their tendency to react with radicals such as active hydrogen atoms retained in an elastomer when such an ionic conductor is composited with such an elastomer, or with minute amounts of water or oxygen atoms contained in the handling environment.
On the other hand, solid polymer electrolytes are considered more advantageous than inorganic solid electrolytes because of their lighter weight, higher flexibility and moldability. However, solid polymer electrolytes are difficult to form into a uniform film, and attempts to improve their uniformity and film moldability resulted in a sacrifice of the ion conductivity of these compositions.